SEOUL (REUTERS) - Covid-19 aid supplies have arrived in North Korea but are being held in quarantine in its seaport of Nampho, the World Health Organisation (WHO) said on Thursday (Oct 7), as the isolated nation shows few signs of easing strict border lockdowns.

North Korea sealed its borders when the coronavirus pandemic began last year, though officials in neighbouring South Korea and the United States have cast doubts on its claim to have never had a case, despite a lack of signs of major outbreaks.

In its latest weekly report for South and East Asia, which covers the period to the end of September, the WHO said it had begun shipments through Dalian, which is near the border with North Korea.

"To support DPR Korea with essential Covid-19 medical supplies, WHO started the shipment through Dalian port, China, for strategic stockpiling and further dispatch to DPR Korea," the agency said, referring to North Korea by the initials of its official name.

The aid in quarantine in the North includes emergency health kits, medicines and medical supplies for essential health services, said Edwin Salvador, the WHO representative to North Korea.

"We are informed that these items, along with others from other UN agencies, remain under quarantine at the seaport," he said in a statement to Reuters.

The supplies went by ship to the North's port city of Nampho after its public health ministry told UN agencies a few months that some aid stranded in China would be let through Dalian's port.

"Consequently, WHO was able to transport some of the items by ship to Nampho seaport," Salvador added.

It had tested at least 40,700 people for Covid-19 with no positive results as at Sept 23, the WHO reported.

Officials in South Korea and the United States have cast doubts on North Korea's claim to have never had a Covid-19 case but no signs of major outbreaks have been confirmed.

An official for South Korea's Unification Ministry, which handles relations with the North, told the Yonhap news agency that while Chinese customs data showed that maritime shipping routes between North Korea and China appeared to be opening, signs of movement of goods through land routes between the two countries had not been detected.